An energy storage device such as a lithium ion secondary battery has been used as a power source for mobile equipment such as a notebook-type personal computer or a mobile phone. In recent years, an energy storage device has been used in various fields including a power source for an electric vehicle.
Conventionally, for such an energy storage device, there has been proposed a technique of estimating a state of an energy storage device based on information such as a charge-discharge history (see patent documents 1, 2, for example). In this technique, the prediction of a lifetime of an energy storage device or the like is performed using information such as a charge-discharge history.